Gliederung

The Boston Retinal Implant Project is developing and testing a chronically-implantable subretinal visual prosthesis. We showed the viability of the concept in a series of six acute epiretinal stimulation trials with blind volunteers between 1998 and 2000. We determined that a subretinal approach provides the safest and most stable placement for the stimulating electrode array and electronics, and have since pursued a chronically-implantable subretinal prosthesis that receives power and data wirelessly.

Our first generation retinal prosthesis was surgically implanted into three Yucatan minipigs, for more than seven months in the longest case. This device was assembled on a flexible substrate which attached to the outside of the eye, deep in the orbit, and the thin-film polyimide flex array with iridium oxide stimulating electrodes entered the subretinal space via an incision in the sclera. Power and data telemetry coils rested on the temporal side of the eye, with the primary coils placed against the temple on the outside of the animal’s head. The implanted device was coated with silicone to protect the electronics, but it was understood that this coating would eventually leak. Our next-generation prosthesis uses a hermetic titanium enclosure to protect the communication and stimulation circuitry. The next-generation Boston retinal prosthesis has been implanted in three minipigs, for more than four months in the longest case.

This lecture is available as video recording (Attachment 1 [Attach.Â 1]).